Tenofovir Disoproxil Fumarate

Tenofovir is eliminated from systemic circulation renally through a combination of glomerular filtration and active tubular secretion. Tenofovir is not a substrate for human organic cation transporter type 1 (hOCT1) or hOCT2. Tenofovir accumulates to fivefold lower levels in MRP4-overexpressing cells, and its accumulation could be increased by an MRP inhibitor. ^[1] Tenofovir produces no significant changes in mitochondrial DNA (mtDNA) levels in human hepatoblastoma (HepG2) cells, skeletal muscle cells (SkMCs), or renal proximal tubule epithelial cells. Tenofovir elevates lactate production by less than 20% in HepG2 cells or SkMCs. ^[2] Tenofovir is efficiently phosphorylated to tenofovir diphosphate (TFV-DP) in both HepG2 cells and primary human hepatocytes. Tenofovir has a 50% effective concentration of 1.1 mM against HBV in cell-based assays, and potency is improved > 50-fold by the addition of bis-isoproxil progroups. Tenofovir has previously demonstrated full activity against lamivudine-resistant HBV in vitro and clinically. ^[3] Tenofovir inhibits the proliferation of liver-derived HepG2 cells and normal skeletal muscle cells with CC(50) values of 398 μM and 870 μM, respectively. Tenofovir shows substantially weaker effects on proliferation and viability of renal proximal tubule epithelial cells than cidofovir, a related nucleotide analog with the potential to induce renal tubular dysfunction. ^[4]

• Cell lines

  VK2 cells

• Concentrations

  450 μM or 1,350 μM

• Incubation Time

  15 min to 12 h

• Method

  VK2 cells were exposed to TDF (90 μM or 450 μM) and TFV (450 μM or 1,350 μM) in serum-free RPMI 1640 at 37°C for 15 min to 12 h. At different times postexposure, cells were washed with ice-cold PBS and metabolites were extracted overnight in 70% (vol/vol) methanol, followed by centrifugation at 18,000 × g for 10 min at 4°C. 

• Animal Models

  BALB/c mice

• Dosages

  50, 500, or 1000 mg/kg

• Administration

  oral administration